xen: add privcmd driver

The privcmd interface in xenfs allows the tool stack in the privileged
domain to get fairly direct access to the hypervisor in order to do
various management things such as domain construction.

[ Impact: new xenfs interface for privileged operations ]

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
diff --git a/drivers/xen/xenfs/super.c b/drivers/xen/xenfs/super.c
index 3cf7707..8c74628 100644
--- a/drivers/xen/xenfs/super.c
+++ b/drivers/xen/xenfs/super.c
@@ -96,6 +96,8 @@
 				  &xsd_kva_file_ops, NULL, S_IRUSR|S_IWUSR);
 		xenfs_create_file(sb, sb->s_root, "xsd_port",
 				  &xsd_port_file_ops, NULL, S_IRUSR|S_IWUSR);
+		xenfs_create_file(sb, sb->s_root, "privcmd",
+				  &privcmd_file_ops, NULL, S_IRUSR|S_IWUSR);
 	}
 
 	return rc;